FJRiders.com

If you have a Gen2, such as my 2007, that DOESN’T run very poorly at minimal throttle openings, what does these measurements look like?

Bike on center stand, trans in neutral, engine running-

At idle-vacuum in inches/hg?

Vacuum at 3000 RPM steady?

MAP voltage under the same conditions?

At steady 3000 does your O2 fluctuate nicely from well above to well below 450mv?

When you transition from “key on engine off” to “engine running” do you lose .1 volt on your 5 volt reference circuit?

Granted, no normal person with a good running bike would be measuring this stuff but on the slim chance that somebody has worked through driveability issues and took a note or two…..

Heaven knows that I’ll have a lot more knowledge about what FJR electrons do by the time I get this thing fixed.

Vacuum measurements taken teed into the MAP sensor hose 1 inch from sensor and voltages backprobed + at ECU and meter grounded to battery neg.
This bike’s had the ECU recall done and a Brodie ground harness installed. TPS looks good and consistent. The MAP sensor plumbing is CLEAN.

Sorry to hear you bike is running poorly. But I love to see an old school mechanic who actually measures stuff to troubleshoot issues, instead of R/Ring everything in sight.

I agree with Bungie. You need to understand where you are compared to "normal" before you can decide where to go!

Can't help you with specific settings or readings but I did have an '07 that had some similar issues. (My two separate issues were related to a MAP sensor line plug and an O2 sensor wire pinched in the timing cover - partly shorted).
A few additional questions that don't answer your request for specific information but might provide some insight into what's going on. I apologize if this is stuff that you have already considered. I don't mean to introduce off-topic stuff before you get any responses.

How many miles?
Compression/leakdown checked?
Has it always been like this or is this new behavior?
If new, what have you done with it lately?
Recent valve check or CCT change?
Better or worse after warmup?
Excessive fuel consumption or evidence of running rich?
Aftermarket cruise control?
Power Commander?
Other electrical farkles?
Assume no error codes?
Have you replaced plugs and how did they look? All the same?

Check that the ECU connector is clean and well seated.
Check that plug caps, wires and continuity are good.
Hard to check without removal but consider that there could be a fuel injector issue.

Good luck with it!

Adding to what Ross said...
The '06-'07 have more severe fuel cut/rewetting issues than any other FJR, thus worse throttle snatch and lean surge in lower rpm range. Improved in '08, tweaked again later I believe, to the point of not needing a Power Commander...
Best thing you can do is have throttle cable freeplay at near zero, when riding twisties, drop a gear and keep the revs up, use engine braking and try to have a little throttle applied as you go in to that next curve (i.e. TB's re-wetted). If you haven't done the throttle spring unwind, it needs it. G2 throttle cam will help. PC may not be necessary, but if one shows up somewhere, I'd grab it and use their stock map. All of that I did on my '07.
Also, next valve check, re-shim all the clearances to ~70% of max, make them all the same near enough as you can. Did this on my '06 project bike which re-used all the '06 ignition and fuel system on a '14 engine... I made the TB's squeaky clean and perfect sync..... never ran better, and better than my '07 did. However, still some of that throttle snatch, it is unavoidable on FI in general, but '06-'07 were not the greatest.
You could try an '08/'09/'10 ECU, being you US guys don't have immobilizers.. memory is bad on who tried that way back, but ABS system is different and may have different signals feeding the ECU... unknown, but if there was a cheap one around, maybe give it a go.
Vacuum readings, will vary a bit but highest when coasting at a constant rpm (say 20 inches), peaking on decel, next highest at idle (bit less), least when accelerating (a lot less), varies with throttle position under load. I wouldn't worry about that much, an engine with good compression is pretty much the same as any other internal combustion engine vacuum-wise. What are you seeing for vacuum under those conditons I mention?
If you haven't, refresh the spark plug wire connections at each spark plug adapter, unscrew & pull them off, trim the wires back 1/4", spread the strands and screw/push the adapters back on... over time you've been pulling on them, vibrations, etc.... can cause minor misfiring at idle.
If MAP sensor voltage in spec, don't worry about it. Good you verified the line is clean (and inside the sensor port as well). A hose plugged will definitely cause idling problems, very noticably.
You can through DiAG cycle the injectors one at a time I believe. Or can pressurize and cycle them... essentially, can look at spray pattern to see if there's a piece of dirt in one (they have filter screens). Or, just take them to an injector test place who will clean them... but I'm kinda doubting there's injector problems, rare on an FJR, but can happen. Try all the other stuff first.

This thread got all techy fast. Has yours ever run well?

I read up on the issues on the early Gen II's and from the get go mine got a PCIII and the Wally Useless Pickles Smoothness map along with a G2 throttle tube and I've been happy ever since.

Techy is what Duane needs. He is the man. If you read his cross country trip from last year, you know he can fix his way out of a bad spot...amazingly so.

EDIT: It looks like Duane found a local 2007 to compare his FJR to. Duane, Phil. Phil, Duane.

raYzerman wrote: ↑Thu Aug 29, 2019 9:52 am
Vacuum readings, will vary a bit but highest when coasting at a constant rpm (say 20 inches), peaking on decel, next highest at idle (bit less), least when accelerating (a lot less), varies with throttle position under load. I wouldn't worry about that much, an engine with good compression is pretty much the same as any other internal combustion engine vacuum-wise. What are you seeing for vacuum under those conditons I mention?

Vacuum is the biggest surprise so far. 10 inches at idle and steady 3000RPM. It goes a little higher, maybe 13 inches, at a steady 5000RPM where the misfire clears up and O2 voltage starts crossing the middle again. In the misfire zone O2 voltage is stuck lean, and the mixture IS lean. For a car mechanic like me 10 inches of vacuum is a bad sign. More to come later but if a good running bike is known to have 18 inches of vacuum at idle like a car then I would start looking at something serious. The bike runs just fine at idle and above 25% throttle.

The problem is a bad misfire at minimal throttle opening. Could also be described as a lean surge or off-idle stumble. Trying to maintain a steady 45 to 65 MPH on level ground results in a bucking bronc experience and rolling through a sweeper with a little power isn’t possible. The bike idles just fine and above about 25 % throttle everything is well too. I would have bet a cross-country ride on a stock seat that the TPS was bad but it measures good at the start and the voltage climbs smoothly.

The bike has 90k on it and all but 4 of those are mine. The problem has just come on in the last 600 miles. The only mods are a K&N filter., G2 throttle tube and a little bump up with the Barbarian Jumper Mod. The last valve check and TB sync was about 10k ago. A couple exhaust clearances were near minimum so I was planning on reshimming this winter. No error codes. The plugs look pretty normal and even.

In the misfire zone (bike stationary) I can manipulate the MAP voltage by a couple hundred millivolts and the misfire will go away and O2 voltage will come off the lean side. All this may be moot because I’m not REALLY duplicating the on road failure with the bike on the centerstand, as real as it may seem. Comparing stationary measurements to known-good values is the only way to satisfy certain curiosities right now. We could end up with a couple DVOMs taped to the tank as we ride down the road

Yikes. So what next??

Ionbeam posted up monitoring TPS while riding, and those things can test OK but be flaky. Possible the MAP sensor is flaky too, dunno. I would look into those seeminly low vacuum readings, but to be honest, I haven't had to look at them before. Minimum valve clearance is fine, as long as there is some clearance, should run OK a couple of thou under minimum. If zero clearance, you're going to see oddities as the valves are not completely sealing. Compression check would say something... leakdown test would nail it down further if an issue.

And now for the carbon build-up chat/low vacuum... I'd do this anyway... get the bike running on fast idle and warmed up well, remove airbox and spray water into each TB, carbon will flake off, buncha steam out the exhaust.... FYB went through this ('07 w/100k) and valve clearances changed (tighter) as carbon was removed, did a couple of valve checks after that to get them back in range. My project bike's original engine was totally carboned up as the PO rode like gramma (also 90k). Note, there are commercial carbon removers such as Gumout, which you spray into the TB's... all good, betcha there's a water content in those. Water/steam and carbon don't mix, that's why it works (you have to be old to remember we did this on our old carbeureted cars).

Another reference for TPS..... yours may be just fine.
https://thebikersgarage.wordpress.com/2 ... otorcycle/

I think you're on the right track with the lean/vacuum condition. You know the tricks to find. (QuickStart) for simple leaks.. if your unlucky, its a sensor compounding a problem. Measurement should reveal that.

I'm not a mechanic, but I've stayed in a Holiday Inn a few times.

raYzerman wrote:Ionbeam posted up monitoring TPS while riding, and those things can test OK but be flaky. Possible the MAP sensor is flaky too, dunno. I would look into those seeminly low vacuum readings, but to be honest, I haven't had to look at them before. Minimum valve clearance is fine, as long as there is some clearance, should run OK a couple of thou under minimum. If zero clearance, you're going to see oddities as the valves are not completely sealing. Compression check would say something... leakdown test would nail it down further if an issue.

And now for the carbon build-up chat/low vacuum... I'd do this anyway... get the bike running on fast idle and warmed up well, remove airbox and spray water into each TB, carbon will flake off, buncha steam out the exhaust.... FYB went through this ('07 w/100k) and valve clearances changed (tighter) as carbon was removed, did a couple of valve checks after that to get them back in range. My project bike's original engine was totally carboned up as the PO rode like gramma (also 90k). Note, there are commercial carbon removers such as Gumout, which you spray into the TB's... all good, betcha there's a water content in those. Water/steam and carbon don't mix, that's why it works (you have to be old to remember we did this on our old carbeureted cars).

Another reference for TPS..... yours may be just fine.
https://thebikersgarage.wordpress.com/2 ... otorcycle/

I agree with this. The only way to truly test a TPS is with a DSO that can catch even the smallest glitch. A hand held DVOM has such a slow update you'll miss the bad spot 101 out of 100 tries.

MAP sensors can have in range failures as well, and a DSO is wonderful for checking them as well, but your problem screams TPS. Quarter throttle, off idle stumble, etc. Some MAPs are analog signals, some are duty cycle based. Not sure on the FJR, but a duty cycle one can be checked with a dwell meter...if you have one of those, you're truly an old fart!

Secondary ignition failures usually occur under high load, so if this happens when just cruising, probably not secondary ignition.

The lean misfire seems to fit the TPS. Throttle open but ECM hears closed from the TPS and squeezes down on the injector pulsewidth.

Whatever the deal, in range intermittent failures just plain suck ass. Shave your head to save the pain of pulling out all your hair.

My stumble fix. 06.
https://candybuttorg.ipage.com/cba/node/765

Replace temperature sensitive TPS (bike quit running once!)
Valve adjust
FI cleaned and balanced
TB sync done
Barbarian mode / Co2 adjusted

Find 2 corroded spark plug leads. $75 for 17k used coils, wires, caps from eBay.

Fixed!

Good luck..

silverback wrote: ↑Fri Aug 30, 2019 11:07 am

raYzerman wrote:Ionbeam posted up monitoring TPS while riding, and those things can test OK but be flaky. Possible the MAP sensor is flaky too, dunno. I would look into those seeminly low vacuum readings, but to be honest, I haven't had to look at them before. Minimum valve clearance is fine, as long as there is some clearance, should run OK a couple of thou under minimum. If zero clearance, you're going to see oddities as the valves are not completely sealing. Compression check would say something... leakdown test would nail it down further if an issue.

And now for the carbon build-up chat/low vacuum... I'd do this anyway... get the bike running on fast idle and warmed up well, remove airbox and spray water into each TB, carbon will flake off, buncha steam out the exhaust.... FYB went through this ('07 w/100k) and valve clearances changed (tighter) as carbon was removed, did a couple of valve checks after that to get them back in range. My project bike's original engine was totally carboned up as the PO rode like gramma (also 90k). Note, there are commercial carbon removers such as Gumout, which you spray into the TB's... all good, betcha there's a water content in those. Water/steam and carbon don't mix, that's why it works (you have to be old to remember we did this on our old carbeureted cars).

Another reference for TPS..... yours may be just fine.
https://thebikersgarage.wordpress.com/2 ... otorcycle/

I agree with this. The only way to truly test a TPS is with a DSO that can catch even the smallest glitch. A hand held DVOM has such a slow update you'll miss the bad spot 101 out of 100 tries.

MAP sensors can have in range failures as well, and a DSO is wonderful for checking them as well, but your problem screams TPS. Quarter throttle, off idle stumble, etc. Some MAPs are analog signals, some are duty cycle based. Not sure on the FJR, but a duty cycle one can be checked with a dwell meter...if you have one of those, you're truly an old fart!

Secondary ignition failures usually occur under high load, so if this happens when just cruising, probably not secondary ignition.

The lean misfire seems to fit the TPS. Throttle open but ECM hears closed from the TPS and squeezes down on the injector pulsewidth.

Whatever the deal, in range intermittent failures just plain suck ass. Shave your head to save the pain of pulling out all your hair.

https://vimeo.com/358084749

channel 1 TPS channel 2 MAP

TPS ordered. We'll see.....

What I'm getting from here most is.....I'm old

I've used water to remove carbon. Honda CVCC cars were horrible about carbon buildup, along with stuck secondary throttle plates, when seldom throttled enthusiastically.

I have a dwell meter. Although, the last time I used it was to count needle sweeps to read Ford EEC-IV DTCs.

Don't worry Duane. I'm sure some young whippersnapper will come along with the solution to your problem.

1911 wrote:What I'm getting from here most is.....I'm old

I've used water to remove carbon. Honda CVCC cars were horrible about carbon buildup, along with stuck secondary throttle plates, when seldom throttled enthusiastically.

I have a dwell meter. Although, the last time I used it was to count needle sweeps to read Ford EEC-IV DTCs.

I always used ATF sucked into a vacuum port. Smokes like Indian tribes at war, but does an amazing job of cleaning the insides of the engine.

My dad had a CVCC Honda Civic. It was a good little car. Needless to say, with my mother behind the wheel, it rarely had closed secondary plates! My dad got her a radar detector for Christmas once and 30 minutes later she was getting another performance award. I jokingly said "Mom, maybe that clip on the radar detector isn't to put it on the sun visor, but a convenient place to store all your tickets." I then learned that you could pick a switch from a tree in someone's yard you don't even know.

I worked on the Ford EEK-4 stuff. Seems like one way to set random codes in it was to read codes from it. Still better than the GM feedback Quadrapuke setup, which, incidentally, used a dwell meter for diagnosis and tuning as well.

On the road so just a quick note. Idle vacuum on a high performance motorcycle engine is good at 10" Hg. As the RMPs goes up, the vacuum goes down. Over 5k RPM the vacuum can drop to 1" - 2" Hg, this is normal and good.

A DMM is plenty fast to read voltage glitching of a bad TPS, no doubt, no question. When the TPS goes through a bad spot in the resistor element the voltage will drop from over a volt to 0.1 to 0.3 volts (approx. it depends on just how bad the resistor element is worn). Even non-technical pillion looking over my shoulder says, 'Wow, look at that' while the engine speed dropped below idle, then whacked back up to 4k RPM as the wiper of the TPS transited across the bad spot in the resistor. The feeling is just like you suddenly shut the throttle off then immediately whacked it open again. In fact that's what happens to the FI system when the TPS voltage suddenly drops and then jumps back up again.

Update

We're watching TPS voltage measured at the ECU, key on engine off. Look what happens as I wiggle the wire harness

https://www.youtube.com/watch?v=MrfEmWduJFY

Hmmmmm.

I'm thinking that's not my fault.